My cousin was in army during Vietnam.He was 18 years old and spent a lot of time fighting in the jungles away from any bases. He went from beginning to smoke cigarettes to any kind of drug he could get his hands on.When he came home he got into drug culture, continuing his drug habits. He has never held down a job, has mental breakdowns, blackouts and suicidal or maniacal episodes.He remains under care of US Veterans and lives off disability. I remember him as a lively, funny younger cousin, but he has been a nearly nonfunctioning adult since Vietnam.He has horrible flashbacks and still will believe during these that he is back in the jungle with his buddies dying all around him.I guess drugs became his escape from the horror of vietnam. Strangely enough he has never drank alcohol. My husband served there during the same period of time and coped much better, never using drugs although growing marjuana was popular around the base he was stationed at.